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Exercise #1 The data below is the population of Northwest Athletic Club members

ID: 3043477 • Letter: E

Question

Exercise #1

The data below is the population of Northwest Athletic Club members enrolled in the Tennis class.

Number (#)

Members Age

Gender

Number of Kids

Attend the swimming classes

1

34

F

2

yes

2

39

F

1

no

3

35

F

1

no

4

25

M

0

no

5

20

M

0

yes

6

37

F

2

yes

7

15

M

0

no

8

22

M

0

yes

9

28

F

1

no

10

25

F

2

yes

11

33

M

3

yes

12

31

M

0

no

13

19

F

0

yes

14

29

M

1

yes

15

27

F

2

no


a) Use the table of random numbers to choose 8 elements of the population. You must specify in which part of the table begins. Explain your procedure.

b) Indicate the average age, the proportion of women, the proportion of those who go to the swimming class, and the proportion of those who have children.

c) Use Excel, creating random numbers, to obtain 8 elements of the population.

d) Indicate the average age, the proportion of women, the proportion of what goes to the swimming class, and the proportion of those who have children.

e) What is the average age of the members?

f) What is the population variance?

g) What is the female population proportion (F)?

Exercise #2


The following indicates a random sample about the costs associated with carpet cleaning service in a city.

$114

$154

$142

$132

$127

$145

$135

$138

$126

$142

$135

$124

The average and standard deviation of the sample are 135 and 10.79, respectively.

a) Find the confidence interval of two tails at 95% confidence level for the population mean, if it is known that the population standard deviation is 12.

b) The confidence interval of two tails to 99% for the population mean, being the population standard deviation unknown.

Do the same procedure but now assuming that the population standard deviation is not known.

c) Find the confidence interval of two tails at 95% confidence level for the population mean.

d) The confidence interval of two tails to 99% for the population mean, being the population standard deviation unknown.

Number (#)

Members Age

Gender

Number of Kids

Attend the swimming classes

1

34

F

2

yes

2

39

F

1

no

3

35

F

1

no

4

25

M

0

no

5

20

M

0

yes

6

37

F

2

yes

7

15

M

0

no

8

22

M

0

yes

9

28

F

1

no

10

25

F

2

yes

11

33

M

3

yes

12

31

M

0

no

13

19

F

0

yes

14

29

M

1

yes

15

27

F

2

no

Explanation / Answer

Part (a)

Use the table of random numbers to choose 8 elements of the population. You. Should specify which part of the table begins.
Explain your procedure
Indicate the average age, the proportion of women, the proportion of those who go to swimming class, and the proportion of those with children.

Solution :

Link for table of random numbers.

http://www.nist.gov/pml/wmd/pubs/upload/AppenB-HB133-05-Z.pdf

I have chosen row 8 column 23 of the table 2 as the starting point. This gives me random numbers

09 12 15 13 08 07 03 01

The procedure to select these numbers is given in the file itself.

Based on this our sample will be,

Part (b)

Use excel, create random number, for 8 elements of the population
Indicate the average age, the proportion of women, the proportion of what they will swim class, and the proportion of those with children.

Solution :-

The random numbers generated using the RANDBETWEEN() function were,

Hence the sample created was,

Part (c)

What is the population average age of members?

What is population variance?

What is the population proportion of women (F)?

Solution :-

Please download the link for excel file in which I have worked from the link given below.

https://www.dropbox.com/s/f1yduxrg333iqjk/random.xlsx?dl=0

Number # age of members gender number of children attends class natacion 9 28 F 1 No 12 31 M 0 No 15 27 F 2 No 13 19 F 0 Yes 8 22 M 0 Yes 7 15 M 0 No 3 39 F 1 No 1 34 F 2 Yes